1. Field of the Invention
The present invention generally relates to a cooling module assembly method and, more particularly, to a cooling module assembly method that can improve cooling efficiency of an assembled cooling module.
2. Description of the Related Art
FIGS. 1 and 2 show a conventional cooling module assembly method. The assembly method firstly couples a circuit board 91 to a first surface 921 of a heat spreader plate 92 by ways of heat pressing, adhering, screwing, etc. A base plate is formed after the circuit board 91 is coupled to the heat spreader plate 92. The heat spreader plate 92 is aluminum having excellent thermal conducting properties and a low specific gravity. The assembly method coats a coupling face 931 of a heat dissipating unit 93 with an adhesive (such as thermal grease) having excellent heat conducting properties, which forms a heat-conducting layer 94 between the heat dissipating unit 93 and the heat spreader plate 92. Hence, a second surface 922 of the heat spreader plate 92 may be adhered to the coupling face 931 of the heat dissipating unit 93. In the same time, a plurality of screw holes 95 is aligned with a plurality of screw holes 932 of the heat dissipating unit 93. The assembly method screws each pair of screw holes 932 and 95 together using a screwing member 96 so that the base plate is closely coupled with the coupling face 931 of the heat dissipating unit 93. Finally, the pins 971 of a plurality of heat-generating elements 97 are soldered on one face of the circuit board 91 to form an electrical connection between the heat-generating elements 97 and a circuit routing embedded in the circuit board 91.
During operation of the heat-generating elements 97, the heat generated by the heat-generating elements 97 will be constantly absorbed by the heat spreader plate 92 via the circuit board 91. In the same time, the absorbed heat of the heat spreader plate 92 will be delivered to the heat dissipating unit 93 via the heat-conducting layer 94. In addition, a plurality of fins 933 is evenly spaced on one side of the heat dissipating unit 93 not coupling with the heat spreader plate 92, thereby increasing the cooling areas of the heat dissipating unit 93. Thus, degraded performance or damages of the heat-generating elements 97 due to high working temperature may be prevented.
In the conventional cooling module, the heat generated by the heat-generating elements 97 is delivered to the fins 933 of the heat dissipating unit 93 via multiple layers such as the circuit board 91, heat spreader plate 92 and the heat-conducting layer 94. However, the circuit board 91, heat spreader plate 92 and the heat-conducting layer 94 are of different materials, which can lead to poor heat conductivity. For example, the circuit board 91 is mainly made of an insulating material such as an epoxy resin or bakelite having poorer heat conductivity. Thus, cooling efficiency of the cooling module is significantly affected. The multiple structures of the cooling module not only reduce the cooling efficiency but also increase the assembly cost of the cooling module.
Moreover, since the heat spreader plate 92 and the heat dissipating unit 93 are made of metal material, the heat-conducting layer 94 is required to be disposed between the heat dissipating unit 93 and the heat spreader plate 92 for enhancing the coupling strength therebetween. Thus, the assembly of the cooling module is more complicated, and assembly efficiency is lowered. In light of the problems, it is desired to improve the conventional cooling module assembly method.